The use of compressed air to inflate the interstice between the two skins of a flexible wall of this type so as to tension the two fabric skins and thus eliminate the folds present on its surface and create a generally smooth appearance on the outside is generally known. Such a device has notably been described in document EP 0 306 717 in which a dual-skin flexible wall has a cord designed to be inserted into a groove in the rigid mount.
In this case, however, once the wall is inflated, the wall section is lens-shaped, each skin of the flexible wall bulging outwards. When these walls are used as tent roofs and subjected to heavy rain, this form of wall can then generate, at each join between two flexible walls, a large rainwater-retention area. Such water-retention areas are particularly inconvenient because they cause water stains, they enable the formation of green algae and are the cause of serious leaks that may occur in the field of industrial tent roofs.
Moreover, such walls require considerable compressed-air energy since the inflated air volume is very large in order to tension the fabrics that form the skins.
Furthermore, the damage of one of the skins of the flexible roof automatically causes the deflation and ruin of the flexible wall. Moreover, it is impossible to use skins made of an open-weave fabric because each of the skins must be impermeable to air.
Furthermore, these lenticular double skins have a very poor insulation capacity in summer and in winter due to the fact that the thickness of the lens thus formed between the two tensioned skins is in the order of 1 meter, a thickness that results in the internal air convection flows being enormous and responsible for large thermal exchanges and therefore for the loss of insulation.
Devices have also been designed such as those described in document DE 33 20 212 in which a cord is placed in an inflatable sleeve then inserted in a groove made in a rigid mount.
However, once the sleeve is inflated, this type of device no longer allows the dual-skin wall to be moved in translation in relation to the rigid mount. In fact, the sleeve deforms and then exerts pressure in the mount groove and immobilises—by virtue of the friction thus generated—the sleeve in relation to the rigid mount. Such inflated sleeve does not, therefore, have a cylindrical form.
Similarly, document DE 90 17 542 describes a device in which a strip is introduced into a groove to immobilise the edges of a dual-skin wall. Such a device has no cord connected with the edges of the two skins and does not allow the wall to be removed once the bead has been inflated. Lastly, with this device it is not possible to achieve an effective tensioning of the wall since, on inflating the bead, the latter may cause the groove strip to dislodge.
The aim of the invention is therefore to create a dual-skin flexible wall with a low inflation volume, designed to tension the two skins, as well as a small air-space separating the two skins.
Another aim of the invention is to prevent the formation of water-retention areas, particularly on the roof of a shelter created using a plurality of flexible walls placed parallel to each other.
Moreover, another aim is also to enable the use of skins made of an open-weave fabric both to create roofs having built-in solar protection, and walls whose inner skin is open-woven to enable the capture and absorption of sound, and lastly to melt snow on the roof and facilitate its drainage in the form of liquid onto a flat surface without pockets.
Lastly, another aim is also to enable movement in translation of the dual-skin wall in relation to a rigid mount when the bead is inflated.